Description

Abstract: Collections of cultivated peanuts, Arachis hypogaea L., and wild Arachis species were screened for resistance to the lesser cornstalk borer, Elasmopalpus lignosellus (Zeller), in naturally infested field plots for 6 years. Plants were scored at harvest time for the number of borer-damaged pegs and pods. Of 120 cultivated lines initially evaluated, 30 selections were tested for each of 5 additional years. As compared with the moderate level of resistance found in the cultivar ‘Florigiant,’ 28 of the selected lines had equal (P = 0.05) or significantly higher levels of resistance (P ? 0.05). A moderately high level of resistance to E. lignosellus in field tests was observed with two ‘Valencia’-type peanuts (subsp. fastigiata var. fastigiata), PI 269116 and PI 275744 and one ‘Spanish’-type peanut (subsp. fastigiata var. vulgaris), PI 262000. The levels of resistance among the 27 wild Arachis species collections tested are not sufficiently high to justify a breeding program for germplasm introgression from wild to cultivated peanuts.